Academic stress detection on university students during COVID-19 outbreak by using an electronic nose and the galvanic skin response

Academic stress is an emotion that students experience during their time at the university, sometimes causing physical and mental health effects. Because of the COVID-19 pandemic, universities worldwide have left the classroom to provide the method of teaching virtually, generating challenges, adaptations, and more stress in students. In this pilot study, a methodology for academic stress detection in engineering students at the University of Pamplona (Colombia) is proposed by developing and implementing an artificial electronic nose system and the galvanic skin response. For the study, the student's stress state and characteristics were taken into account to make the data analysis where a set of measurements were acquired when the students were presenting a virtual exam. Likewise, for the non-stress state, a set of measurements were obtained in a relaxation state after the exam date. To carry out the pre-processing and data processing from the measurements obtained previously by both systems, a set of algorithms developed in Python software were used to perform the data analysis. Linear Discriminant Analysis (LDA), K-Nearest Neighbors (K-NN), and Support Vector Machine (SVM) classification methods were applied for the data classification, where a 96 % success rate of classification was obtained with the E-nose, and 100 % classification was achieved by using the Galvanic Skin Response.

Scalable interrogation: Eliciting human pheromone responses to deception in a security interview setting

Individuals trying to conceal knowledge from interrogators are likely to experience raised levels of stress that can manifest itself across biological, physiological, psychological and behavioural factors, providing an opportunity for detection. Using established research paradigms an innovative scalable interrogation was designed in which participants were given a 'token' that represented information they had to conceal from interviewers. A control group did not receive a token and therefore did not have to deceive the investigators. The aim of this investigation was to examine differences between deceivers and truth-tellers across the four factors by collecting data for cortisol levels, sweat samples, heart-rate, respiration, skin temperature, subjective stress ratings and video and audio recordings. The results provided an integrated understanding of responses to interrogation by those actively concealing information and those acting innocently. Of particular importance, the results also suggest, for the first time in an interrogation setting, that stressed individuals may secrete a volatile steroid based marker that could be used for stand-off detection. The findings are discussed in relation to developing a scalable interrogation protocol for future research in this area.

Gender effects and sexual-orientation impact on androstadienone-evoked behavior and neural processing

In humans, the most established and investigated substance acting as a chemosignal, i.e., a substance that is excreted from the body, is 4,16-androstadien-3-one (AND). AND, which is found in sweat and saliva, is known to be responsible for influencing several variables, such as psychophysiological status, behavior, as well as cortical processing. The aim of the present review is to give insight into the variety of AND effects, with special regard to specific cross-sexual characteristics of this putative human chemosignal, emphasizing the neural activation patterns and factors such as contextual conditions. This review highlights the importance of including those contributing factors into the analysis of behavioral as well as brain-related studies.

Localisation of unilateral nasal stimuli across sensory systems

Odor stimuli presented to one nostril can only be localised if they additionally activate the trigeminal nerve's chemosensitive fibers. In this study we aimed to investigate characteristics in the localisation of unilateral trigeminal, olfactory and somatosensory nasal stimuli. We compared the ability of healthy young subjects to localise monorhinally presented (a) pure olfactory stimuli (phenyl ethyl alcohol), (b) mixed olfactory trigeminal stimuli (eucalyptol), and (c) somatosensory stimuli (air puffs). As expected, subjects could localise the air puffs and eucalyptol, but could not phenyl ethyl alcohol. Interestingly, we observed a significant correlation between localisation performance for eucalyptol and phenyl ethyl alcohol but not between the ability to localise somatosensory and trigeminal or olfactory stimuli. These observations show that on a behavioural level, the trigeminal chemosensory system is more intimately connected to the olfactory system than to the somatosensory system despite the fact that anatomically its information is conveyed via same nerve as the latter. Furthermore, they show that the trigeminal chemosensory system should therefore be considered a self-confined contributor to chemosensory perception.